In non-English mailing lists (particularly in Russian) there is a
big problem with messages, where charset parameter of Content-Type
header is set incorrectly. Sometimes software is buggy, sometimes
people cannot set up their software properly, sometimes web-based
email clients do not implement charsets. While reading such a
mail, one should manually switch encoding in MUA back and forth.
Incorrectly encoded or plain 8-bit Subject field is another big
problem. Such fields often get corrupted while passing e-mail
gateways.
This program can be used to solve this problem while used as mail
filter (in MTA, procmail, or a similar program).